Sharing service does not handle reconnect nicely

[StephenHodgson]

Race condition in the native sharing service that does not raise OnSessionAdded in time.

We know we're connected to the session list server, but IsConnected is raised before we add each session to the Sessions list in ServerSessionsTracker and we get a mismatched count when auto joining a session.

Workaround is to add a timeout in the AutoJoinSessionAndRoom that just waits a second or two before starting the coroutine.